Enhanced cadmium (Cd2+) removal from wastewater using integrated inclined plate settler and composite adsorbent coating

• Published in: Applied water science Vol. 14; no. 10; pp. 225 - 17
• Main Authors: Chintokoma, Gilbert C., Chebude, Yonas, Kassahun, Shimelis K., Demesa, Abayneh G., Koiranen, Tuomas
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.10.2024; Springer Nature B.V; SpringerOpen
• Subjects: Adsorbents; Adsorption; Aquatic Pollution; Aqueous solutions; Breakthrough curve; Cadmium; Comparative Law; Composite adsorbent coating; Earth and Environmental Science; Earth Sciences; Flow rates; Flow velocity; Heavy metals; Hydrogeology; Inclination angle; Inclined plate settler; Industrial and Production Engineering; Industrial wastes; Industrial wastewater; Industrial wastewater treatment; Influents; International & Foreign Law; Nanotechnology; Optimization; Original Article; Plates; Private International Law; Response surface methodology; Settlers; Synergistic effect; Synergistic integration; Waste Water Technology; Wastewater treatment; Water Industry/Water Technologies; Water Management; Water Pollution Control; Water treatment; Inclination angle; Composite adsorbent coating; Inclined plate settler; Optimization; Synergistic integration; Breakthrough curve
• ISSN: 2190-5487; 2190-5495
• DOI: 10.1007/s13201-024-02292-2

Bottlenecks inherent in batch and column adsorption configurations have impeded the implementation of the adsorption technique in large-scale wastewater treatment systems. This study mainly aimed to develop an innovative wastewater treatment prototype that integrates inclined plate settlers (IPS) and composite adsorbent coating (CAC). The objective is to enable the removal of Cd 2+ from aqueous solutions in a continuous setup, thereby enhancing its practicality for large-scale applications. The combined IPS-CAC system was optimized at various angle of inclination ( θ ), influent flow rate ( Q ) and adsorbate initial concentration ( C o ) using the Box–Behnken Design (BBD) of the Response Surface Methodology (RSM). At optimized operating parameters ( θ  = 45°, Q  = 5 ml/min and C i  = 1.87 mg/L) the IPS-CAC Cd 2+ predicted ( R 2  = 0.9926) and experimental removal efficiencies were 75.8% and 69.7 ± 4.67%, respectively. The IPS-CAC breakthrough adsorption capacity was 9.6 mg/g. Comparing IPS-CAC performance with a tank without plates and IPS with plain plates, the Cd 2+ removal efficiencies were 2.4 ± 0.1% and 4.6 ± 1.1%, respectively, confirming the synergistic effect of IPS and CAC. Additionally, breakthrough curves were acquired for various flow rates, cadmium influent concentrations, and plate inclination angles. Only a 10% decline in the removal effectiveness (from 69.7 to 59.7%) of the CAC after three adsorption–regeneration cycles was observed, indicating its stability for heavy metal removal. The results underpin the potential of using IPS-CAC for industrial wastewater treatment and enhancing the use of adsorption on a larger scale.